Re: Dust inside my new 135mm GM. Should I even worry about it?
Sinasina wrote:
Oh, this is super embarrassing. I have not read the article, only looked at the pictures and thought that the sealing is pretty good & there should not be any dust in a new lens based on that. What a blunder, both by me and Sony. Don't use this lens in the rain I guess I don't even dare to think where the dust is getting in from at this point..
Weather sealing does not create an air tight seal and the ability of a lens to prevent water ingress has little to do with dust getting in the lens.
Lenses suck in air when the focus elements move and when zooming. This is an essential feature of every consumer camera lens, if air did not flow through the lens it could not move and thus could not focus or zoom. Sucking in air can suck in small particles of dust. Generally speaking, zoom lenses tend to be the most susceptible to internal dust, as they have to suck in a lot of air. Fast prime lenses that need to move large focus elements tend to be a problem too.
Additionally, any time the lens spends off the camera, it is not sealed (attaching a sealed lens to a sealed camera completes the seal), it's fairly easy for dust to get in through the rear of the lens with most lens designs. The rear seal is generally at the lens mount, so it won't stop dust from getting in that floats in when changing lenses or happens to be on the rear lens cap.
Small particles of dust are common even with new lenses across all brands. This is unlikely to be a matter of Sony being cheap, having poor quality control, or a poorly designed lens. Assuming we're talking about a small particle of dust, not a chunk of debris of course.
Contrary to popular belief, a small amount of dust inside a lens will not hurt its resale value - in fact every lens should be assumed to have at least a small amount of dust. If you can't spot dust in your lenses, you're not looking hard enough. So the only way the resale price would drop is if you freak out about the dust and make a big fuss over it in the listing.
Dec 01, 2019 at 11:30 AM
Previous versions of EarthQuake's message #15061817 « Dust inside my new 135mm GM. Should I even worry about it? »
I don't even dare to think where the dust is getting in from at this point..